While metallic glass has existed for decades, the majority of people became aware of its revolutionary properties when it was introduced as a product by Liquidmetal Technologies. Many people have seen our popular ”bouncing ball” demonstration on Youtube, where ball bearings dropped on plates of steel and titanium stop bouncing after a few seconds, while the ball on a plate of Liquidmetal seems to bounce well over a minute.
But what causes this amazing, apparently gravity-defying behavior, and more importantly, how can we use this property to our advantage?
First, the primary difference between Liquidmetal and almost every other metallic solid is that the atoms that make up each Liquidmetal part have no order or pattern to their arrangement. Instead, the atoms appear as if they belong to a liquid rather than a typical solid where atoms appear in the regular, repeating geometric patterns characteristic of crystalline structures.
Second, this unusual atomic structure affects the way the material behaves. Most materials deform when you hit them with something hard like a hammer. Liquidmetal however, retains its original shape. In scientific terminology, this is called having a high “coefficient of restitution”. It means that the energy stored in the hammer when it hits the Liquidmetal does not re-arrange atoms as it would in other metals. Instead, energy is transferred back to the hammer. The bouncing-ball demonstration is, therefore, a measurement of the coefficient of restitution. For example, if you drop the ball from a height H1 and on the first bounce the ball reaches a height of H2the coefficient of restitution can be found by the equation
Coefficient of Restitution = e = (H1/H2)1/2
Another way to identify energy loss is simply to look for visible signs that the atoms in a material have moved after an impact. Those shifts can appear as dents, dimples, or another defect in the surface. When compared with titanium or steel, the Liquidmetal plates look almost untouched after years of performing the bouncing ball demo to amazed audiences.
Liquidmetal has been used to improve the performance of products. It also makes an excellent ruggedized casing and hinge, retaining its exact original shape after thousands of flexes. How can you put this property to work for your application?